The present invention relates generally to the field of electrical cords for power tools, and, more particularly, to a water resistant, load-bearing coupling for a power tool.
Electrical power tools are commonly provided with a male plug adapted to fit into a female receptacle of a power cord, particularly an extension power cord adapted to be plugged into a wall outlet or the like. Once made up, the connection provides electrical power to the power tool to run the tool. Users commonly use the power tool at some distance from the outlet, or even at some height above the outlet, so that the connection of the power cord to the tool, which typically relies primarily on friction to remain coupled, tends to come apart.
Electrical cord connections commonly in use today suffer from other drawbacks. Particularly, power tools using electrical extension cords are often used in environments in which the coupling of the cord is likely to come in contact with water or other liquids, or even be immersed in such a liquid. However, most electrical plugs which provide power to tools are not water proof or even water resistant. This problem with commonly used plugs may therefore present a safety hazard.
Commonly used cord connections also suffer from the drawback in that, even if such connections provide a means to keep the male end plugged into the female end, the means is seldom strong enough to keep the connection made up if the user drops the tool, or wishes to hoist the tool to the working location by the expedient of lifting the tool by the cord.
A number of connectors have been proposed to help to keep electrical plugs made up. For example, in U.S. Pat. No. 6,080,004, Kovacik et al. taught an electrical connection comprised of a pair of cooperating separable plug members having a separable locking yoke. The yoke defines legs, the ends of which are pivotally mounted to boss members formed on one of the plug members. The yoke further defines a pair of cooperating spaced apart elements for frictionally engaging the electrical conduit leading away from the other of the pug members. This plug lock helps to keep the plug members from coming apart, but the connection is not robust enough to permit substantial stress from being applied to the electrical cord. Further, the connection does not provide a water resistant seal.
Thus, there remains a need for an electrical cord connection that provides a positive means of maintaining an electrical connection, while sealing the connection in a manner that is resistant to the intrusion of water. The connection should be inexpensive and simple to manufacture and use, and should provide enhanced safety. The connection should also be robust enough to allow the user to lift a tool connected to an extension cord in a safe and expeditious manner. The present invention is directed to such an electrical connector.
The present invention addresses these and other needs in the art by providing an electrical coupling having a sealing element, a mechanical securing element, and load bearing members on either side of the mechanical securing element. The load bearing members each comprise upper and lower body halves, which mount to an inner member through which an insulated electrical cable runs. Between the upper and lower body halves and the inner member, an open weave fabric is secured, and the fabric extends onto the electrical cable beyond the load bearing member, so that when stress is applied to the cable, the fabric tends to squeeze down onto the cable, thereby bearing the stress on the cable.
Although other structures may be used within the spirit and scope of the invention, the mechanical securing element is preferably a bayonet mount. The bayonet mount is preferred principally because it provides a strong means of securing male and female ends together. The bayonet mount also provides the advantageous feature of sliding along axially, thereby permitting easy access to electrical component within the connector for repair and maintenance. The bayonet mount also includes an O-ring seal, making the connector water resistant when made up.
While the load bearing member has been described as adapted to take up the stress of an electrical cord in a connector, the load bearing member feature of the invention may also be applied to a hard wired connection to a hand tool, for example. The upper and lower members which retain the open weave fabric may be part of or attached to the butt end of a hand tool to absorb the strain of the cord to lessen the likelihood of pulling the cord out of the hand tool.
These and other features and advantages of this invention will be readily apparent to those skilled in the art.